EPA Mercury Air Emissions from Gold Mines Rulemaking

The Environmental Protection Agency (EPA) recently announced a proposed rule limiting mercury air emissions from gold mines. This rule would apply to the Donlin Creek Mine, but the rule does not go far enough to protect people and the environment.

Mercury Cycle, Ground Truth Trekking

The Environmental Protection Agency (EPA) recently announced a
proposed rule limiting mercury air emissions from gold mines. This rule
would apply to the Donlin Creek Mine, but the rule does not go far
enough to protect people and the environment.

Mercury is a naturally occurring metal and is often found in a rock
called "cinnabar." This rock was historically mined along the Kuskokwim
River, and mercury was in mining waste and continues to be released into
the environment from these old mines. The Donlin Creek Project is
located in the "mercury belt" of Alaska, a geologic zone of Alaska where
mercury is found in many rock formations. As a result, mining and
milling activities at the mine will produce both point source and
fugitive source mercury emissions.

EPA's proposed rule will regulate the amount of mercury air emissions
from point sources at mines-stacks and vents. As it is proposed, the
rule would limit emissions for pre-treatment processes (roasters and
autoclaves) to 149 lb/ton of ore processed at both new and existing
mines. The Donlin Creek Mine intends to process 22 million tons of ore
per year. That means that under the proposed rule, Donlin Creek could be
permitted to emit over 3200 pounds of mercury per year, just
from pre-treatment processes.

Additionally, the rule limits mercury emissions for carbon
concentrate processes to 2.6 lb/ton of concentrate for existing mines
and 0.14 lb/tons of concentrate or a 97% reduction in uncontrolled
emissions for new mines. This will allow the Donlin Creek Mine to emit
additional mercury. Further, the rule does not limit emissions from
fugitive sources at the mine-waste rock piles and tailings ponds. Thus,
the total mercury air emissions from the mine will be even higher.

For comparison, 2008 Toxic Release Inventory data from the EPA
indicates that 71 pounds of mercury was emitted into the air in Alaska
that year. This means that under the proposed rule, the Donlin Creek
Mine would increase mercury air emissions in Alaska more than 40 times.

Additionally, the proposed rule only requires annual monitoring;
monitoring needs to be more frequent.